"Well a full disclosure here, I'm not feeling too well," Roberts, 51, announced midway through Tuesday's broadcast. "In fact, I'm going to leave, and let you all do the rest of the program on your own. I'm going to take a little time off, just to get some vacay. I'll see you in a couple of weeks."

Suffering a sore jaw as a result of her treatment for myelodysplastic syndrome (MDS), Roberts remained in good spirits and joked with colleague Josh Elliott when she had trouble pronouncing a word. "I can't talk on this side of my mouth," she said. "We're going to miss you, but we do appreciate the Jimmy Cagney impersonation before you leave," Elliott kidded back.

A breast cancer survivor, Roberts revealed she was suffering from MDS in June. ABC tells The New York Daily News that the beloved anchor originally intended to go on vacation around this time anyway, and that she is planning to return to work later this month before her transplant.

"I slept like a baby last night for the first night since my diagnosis," Roberts told GMA viewers the day after going public with her health struggle. "My family and I are overwhelmed and comforted by the response from everyone.

Roberts' sister is expected to be her marrow donor. "I am very fortunate to have a sister who is an excellent match," the anchor has said. "This greatly improves my chances for a cure."